The present study will monitor and explore acute neurovascular emergencies in patients treated with NOACs compared to those under treatment with VKAs. The primary aims of this study are: (1) To investigate characteristics, management and outcome of intracranial hemorrhage (ICH) in patients treated with NOAC compared to VKA. (2) To investigate the management and outcome of patients with acute ischaemic stroke under NOAC compared to VKA.

Background: For decades, oral anticoagulation with vitamin K antagonists (VKA) has been the sole option for the treatment of a variety of diseases like venous thrombosis, pulmonary embolism and the prevention of stroke in patients with atrial fibrillation. Despite its clinical efficacy, the treatment with VKA is associated with multiple well-known limitations, including a significant risk of major hemorrhages (especially intracerebral hemorrhage), food and drug interactions, and the need for continued coagulation monitoring for dose control. Recent randomised controlled trials (RCT) have provided promising results with novel oral anticoagulants (NOAC) that do not exhibit the limitations of VKA. Especially for stroke prevention in patients with atrial fibrillation, NOAC have shown comparable or even better protective efficacy while causing less intracerebral hemorrhages (ICH). Eventually, this has led to the marketing approval of Apixaban, Rivaroxaban and Dabigatran for stroke prevention in patients with atrial fibrillation by the Swiss Health Authority (Swissmedic).

Even though the trials reported on the occurrence of acute ischemic strokes or intracerebral hemorrhages in patients under the treatment with NOAC, only limited data and few case reports have been published so far. Thus, aspects concerning the treatment decisions and concepts of management of acute ischemic stroke under NOAC were not addressed in these trials; in particular, the use of acute revascularisation therapies like intravenous thrombolysis (IVT) or intra-arterial treatment (IAT) remains unanswered. Furthermore, characteristics, management and outcome of ICH under the treatment with NOAC were not addressed. Thus, information on relevant aspects of the management of acute neurovascular emergencies under NOACs remains scarce.

Aims: The present study will monitor and explore acute neurovascular emergencies in patients treated with NOACs compared to those under treatment with VKAs. The primary aims of this study are: (1) To investigate characteristics, management and outcome of intracranial hemorrhage (ICH) in patients treated with NOAC compared to VKA. (2) To investigate the management and outcome of patients with acute ischaemic stroke under NOAC compared to VKA.

Methodology: We launch an observational, multi-center (Switzerland and Europe) registry. The leading and coordinating center is located at the Stroke Center of the University Hospital Basel. The following groups of patients admitted to a Stroke Unit of one of the participating centers will be enrolled: A) Patients with ICH occurring while under the treatment with NOAC (last intake <48 hours) or VKA and B) Patients with acute ischaemic stroke occurring while under treatment with NOAC (last intake <48 hours) or VKA.

Inclusion Criteria:

• Patients with ICH occurring while under treatment with NOACs (last intake <48 hours) or VKAs for any indication;
• Patients with acute ischaemic stroke occurring while under treatment with NOACs (last intake <48 hours) or VKAs for any indication.

Exclusion Criteria:

• The patient is, in the opinion of the investigator, unlikely to comply with the clinical study protocol or is unsuitable for any other reason.
• Patients <18 years of age

patients admitted to the Stroke Unit at the University Hospital Basel (leading and coordinating center).